With widespread use of smartphones and tablets, mobile communication technologies like long term evolution (LTE) and data communication technologies like wireless local area network (LAN) are broadly becoming popular. Such various data communication technologies have advantages and disadvantages. For example, when the LTE is compared with the wireless LAN, the LTE has a wide radio coverage area, while the wireless LAN is low in cost for fast-speed communication.
Hence, communication techniques combining multiple data communication technologies have been developed in order to make full use of advantages of respective technologies. For example, Patent Literature 1 discloses a technique of enabling a communication terminal, which does not have an interface to be connected to a mobile communication network like LTE but has an Internet Protocol (IP) interface, to utilize a service over the mobile communication network.